1. Technical Field
The present invention relates to a work transfer apparatus that moves up and down and transfers a workpiece such as a mechanical component or an electronic component, and more particularly to a work transfer apparatus that can transfer a workpiece that is carried step by step by a transferring mechanism such as a rotation table onto a processing table arranged in a predetermined processing area.
2. Description of the Related Art
As a conventional work transfer apparatus, there is known an apparatus which includes: a rotation table that has a plurality of concave portions for accommodating workpieces (chip components) in a peripheral region and is driven to rotate in a predetermined angle steps; a carrier tape that is arranged to be adjacent to the rotation table; an actuator that is arranged like a cantilever above the carrier tape and the rotation table and moves a vacuum head in a vertical direction; and which has a configuration that the vacuum head is utilized to adsorb each workpiece while moving the vacuum head by the actuator, thereby transferring the workpiece onto the carrier tape from the rotation table (se, e.g., Unexamined Japanese Patent Publication No. 2004-18054).
Further, as another work transfer apparatus, there is known an apparatus which includes: a rotation table that has a plurality of vacuum holders for adsorbing and holding workpieces (chips) in a peripheral region and is driven to be rotated in a predetermined angle steps; a chip pedestal arranged to face the vacuum holders in a state where the rotation table is stopped at a predetermined angle position; a lifting and lowering device that drives the chip pedestal to move up and down; and which has a configuration that each workpiece on the chip pedestal is adsorbed and held by the vacuum holder by driving the chip pedestal to move up and down by the lifting and lowering device and appropriately driving the rotation table to rotate, thereby transferring the workpiece to a predetermined area (see, e.g., Unexamined Japanese Patent Publication No. 10-4132).
However, in these apparatuses, since the workpiece is transferred while being adsorbed and lifted, no problem occurs when the workpiece is a small and lightweight piece like an electronic component (a chip), but adsorbing and holding the workpiece at a predetermined position is difficult when transferring the workpiece that is a large and heavy workpiece like a mechanical component.
On the other hand, as a conventional index type production apparatus, there is known an apparatus which includes: a plurality of rotation tables (index tables) that are capable of supporting workpieces and are driven to rotate in a predetermined angle steps; a work unit that is arranged to be adjacent to each of the plurality of rotation tables to perform a predetermined work; a plurality of rotating arms each of which is arranged between adjoining rotation tables and has a chuck that grasps a workpiece; and which has a configuration that a workpiece subjected to a predetermined work is grasped to be sequentially transferred from the rotation table to another rotation table (see, e.g., Unexamined Japanese Patent Publication No. 2006-347717).
However, in this apparatus, since each work is carried out on the rotation table by the work unit, when performing a work that applies a load (e.g., pressurization or press fitting), each rotation table must be sturdily formed to bear the load. Further, since a workpiece transfer operation is carried out by each rotating arm that requires an operation of lifting/lowering, rotation and lifting/lowering in the mentioned order, this operation cannot be smoothly performed, and each rotating arm must be sturdily formed when the workpiece is a heavy piece, thus leading to an increase in size or in cost of the apparatus.